Pass the Huawei HCIE-Datacom H12-891_V1.0 Questions and answers with CertsForce

InOSPFv3,Link-LSA (Type 8)is generated by a routerfor each of its interfacesto advertise:

Therouter's link-local addresson that interface.

TheIPv6 prefixesassociated with the interface.

Flags and options, such as router priority or loopback indicators.

From the output:

Link-LSA (Interface GigabitEthernet0/0/0)

Originating Router: 10.1.2.2

Link-Local Address: FE80::2E0:FCFF:FECD:4F79

Prefix: 2001:DB8:2345:23::/64

A. The link-local address of R2’s GE0/0/0 is FE80::2E0:FCFF:FECD:4F79→ This matches the Link-Local Address field in the LSA.✅

B. The IPv6 address prefix of R2’s GE0/0/0 is 2001:DB8:2345:23::/64→ This matches the Prefix field in the LSA.✅

C. This LSA indicates that R2 does not support external routes but can participate in IPv6 route calculation→❌Incorrect.

TheLink-LSAdoesnot provide any indicationabout external route capabilities.

It simply advertisesinterface-specific IPv6 and link-local info.

Whether R2 supports external routes depends onType 5 (External) or Type 7 (NSSA) LSAs, not Link-LSAs.

D. This LSA is generated by R2→ The Originating Router: 10.1.2.2 is R2’s router ID, so this LSA is definitely generated by R2.✅

Correct Answers:A, B, D

The Link-LSA in OSPFv3 contains:

The link-local address used by the originating router on the link.

A list of all IPv6 prefixes associated with the link.

Flags such as router priority and the Router-LSA options.

These LSAs are alwaysgenerated by the router itselfand arenot flooded beyond the link.

Understanding Network Monitoring Data Categories

????Network devices operate across three functional planes:

✅A. Management Plane:

Handlesdevice configuration, authentication, and monitoring.

Example:SNMP, SSH, NETCONF logs.

✅B. Data Plane (Forwarding Plane):

Handlespacket forwarding and switching.

Example:Interface statistics, traffic rates, dropped packets.

✅C. Control Plane:

Handlesrouting, signaling, and protocol operations.

Example:BGP, OSPF, and MPLS signaling messages.

❌D. Monitoring Plane (Incorrect Choice):

There is no "monitoring plane" in network architecture.

Monitoring tools collect data frommanagement, control, and data planes, butdo not form a separate plane.

Why is the Answer D (Monitoring-plane data)?

❌Monitoring-plane does not exist as a separate category in network architecture.

✅O&M tools collect data from management, control, and data planes, but do not define a separate "monitoring plane".

Real-World Application:

Huawei iMaster NCE-Campus & iMaster NCE-WANcollect real-timenetwork statistics and alarms.

Network Performance Monitoring (NPM)toolsanalyze control-plane eventsto detect failures.

✅Reference:Huawei HCIE-Datacom Guide – Network Planes and Performance Monitoring

Understanding Inter-AS MPLS VPN Option C (Solution 2)

In MPLS L3VPN Inter-AS Option C, the Route Reflectors (RRs) are used for VPN route distribution but do not participate in data forwarding. The traffic forwarding path is based on MPLS labels assigned at different routers.

Each data packet carries two MPLS labels:

Transport Label (T1) – Used for forwarding within the backbone.

VPN Label (V1) – Used for VPN route identification.

Breaking Down the Labels:

✔VPN Label (V1) – Allocated by PE1 (Answer: C✅)

V1 (Inner Label) is the VPN label assigned by the egress PE router (PE1).

This label ensures that when the packet reaches PE1, it knows how to forward the traffic to CE1 (192.168.1.1).

✔Transport Label (T1) – Allocated by P2 (Answer: B✅)

T1 (Outer Label) is the transport label assigned by P2 to forward the packet across the AS core.

This label ensures the packet reaches the next-hop router (ASBR-PE1 in AS100).

Why Are the Other Options Incorrect?

❌A. "T1 is allocated by RR2" (Incorrect)

RR2 is used only for route reflection; it does not participate in label allocation or forwarding.

❌D. "V1 is allocated by P2" (Incorrect)

P2 is an intermediate router and does not allocate VPN labels.

VPN labels are always assigned by the egress PE router (PE1 in AS100).

????Reference:Huawei HCIE Datacom – MPLS L3VPN Inter-AS Option C

Understanding 6PE & 6VPE in MPLS Networks

6PE (IPv6 Provider Edge) and 6VPE (IPv6 VPN Provider Edge) areMPLS-based solutionsthat allowIPv6 trafficto be carried over anMPLS IPv4 core networkwithout requiring the entire backbone to support IPv6.

????6PE (IPv6 over MPLS - No VPN)

Used forglobal IPv6 routingwithout VPN segmentation.

No need forVRFs (VPN Routing and Forwarding instances)because IPv6 prefixes arehandled natively.

????6VPE (IPv6 VPN over MPLS - Supports VPNs)

ExtendsMPLS L3VPNto supportIPv6 routing inside VPN instances.

UsesMP-BGP VPNv6to distribute IPv6 prefixes insideMPLS VPNs.

Why is the Answer TRUE?

✅No VRFs are required for 6PE:

6PEonly needs BGP labeled IPv6 routesin theglobal routing table.

IPv6 prefixes are carried usingMPLS labelswithout VPN segmentation.

✅VRFs are required for 6VPE, NOT for 6PE:

6VPE requires VPN instances (VRFs)forIPv6 L3VPNs, but6PE does not.

✅Real-World Application:

6PE is used in large ISP networkswhere IPv6 deployment is needed butwithout VPN separation.

6VPE is used for enterprise MPLS VPNs, allowing customers to haveisolated IPv6 routing tables.

✅Reference:Huawei HCIE-Datacom Guide – MPLS IPv6 Transition Technologies (6PE & 6VPE)

Traffic Diversion in SR-MPLS Policy

SR-MPLS Policiesuse traffic steering mechanismsto direct specific flows toSegment Routing paths (SR Policies). When multiple services share thesame destination address,color-based traffic diversionensuresdifferentiated service treatment.

✅B. Color-based traffic diversion (Correct Answer)

Traffic is classified based on "color" (a BGP-SR policy attribute) and mapped to different SR-MPLS tunnels.

Different colors represent different paths(e.g., high-priority services can use an optimized low-latency path).

This method ensures service qualityby directing traffic according topolicy-based routing decisions.

Let’s break this down step-by-step based on Huawei IS-IS VPN and multi-process behavior.

???? Configuration Summary:

Process 1: IS-IS for the global routing table

Process 2: IS-IS for VPN instance tt

Process 3: IS-IS for VPN instance rr

✅ Option C: Correct

Process 1 contains only global routing information.

The configuration of isis 1 does not include any vpn-instance keyword, meaning it is bound to the global routing table.

It does not interact with VPN routing tables unless explicitly configured with import/export mechanisms or route leaking (which is not shown here).

Huawei Datacom Reference:

“When an IS-IS process is not associated with a VPN instance, it belongs to the global routing table and only maintains global routes.”

(Source: HCIE-Datacom Study Guide v3.0 – Chapter: IS-IS for IPv4 and IPv6, Section: Multi-Instance Routing)

✅ Option D: Correct

Routing information of process 2 is isolated from that of process 3.

isis 2 is bound to VPN instance tt

isis 3 is bound to VPN instance rr

Each IS-IS process in Huawei VRF context maintains independent LSDBs and routing tables, and by default, they do not share routing information unless route leaking or redistribution is configured (which is not shown in the config).

Huawei Datacom Reference:

“IS-IS processes bound to different VPN instances operate independently and do not share routing information.”

(Source: HCIE-Datacom Study Guide v3.0 – Chapter: MPLS L3VPN with IS-IS)

Comprehensive and Detailed Explanation:

✔MPLS labels in SR-MPLS are calculated using the SRGB (Segment Routing Global Block) baseand thePrefix-SID.

✔Label Calculation Formula:

MPLS Label=SRGB Base+Prefix-SID\text{MPLS Label} = \text{SRGB Base} + \text{Prefix-SID}MPLS Label=SRGB Base+Prefix-SID

✔Extracting Values from the LSDB:

SRGB Base:36000

Prefix-SID:300

✔Valid MPLS Labels:

36000 + 300 = 36300

40002 and 38002 fall within the SRGB range.

39002 is outside the expected range, making it theincorrect answer.

????Reference:Huawei HCIE Datacom – Segment Routing Label Calculation

A screenshot of a computer AI-generated content may be incorrect.

IPsec (Internet Protocol Security) provides secure communication over IP networks by implementing multiple security functions.

✔Data Origin Authentication:

Ensures that the sender of the data is genuine and not impersonated.

Uses techniques such as HMAC (Hash-Based Message Authentication Code).

Correct Match:"The receiver verifies the identity of the sender."✅

✔Data Encryption:

Protects data confidentiality by encrypting packets using AES, 3DES, or other encryption algorithms.

Ensures that only the intended recipient can decrypt the data.

Correct Match:"The sender encrypts the data, and the receiver decrypts the data."✅

✔Data Integrity:

Ensures that data is not altered in transit.

Uses cryptographic hashes (e.g., SHA-256) to verify integrity.

Correct Match:"The receiver verifies received data to determine whether the data has been tampered with."✅

✔Anti-Replay:

Protects against packet replay attacks, where an attacker resends captured packets to disrupt communication.

Uses sequence numbers to detect and reject duplicate packets.

Correct Match:"The receiver rejects duplicate data packets."✅

????Reference:Huawei HCIE Datacom – IPsec Security Functions

Ethernet Segment Identifier (ESI) is a 10-byte identifier used in EVPN (Ethernet VPN) to uniquely identify an Ethernet segment across a network, particularly in multi-homing scenarios. It ensures loop prevention and redundancy.

Exact Extract - HCIE-Datacom EVPN Section:

“The ESI is a 10-byte identifier and must be unique across the entire EVPN network. It plays a key role in identifying Ethernet segments in multi-homed environments.”

Understanding MPLS LDP and PHP (Penultimate Hop Popping):

✔Label Distribution in MPLS LDP:

LDP assignslabels to FECsso that routers can forward packets based on labels rather than IP lookup.

Labels areadvertised downstream(from R4 to R3, R3 to R2, and so on).

✔Penultimate Hop Popping (PHP) Concept:

Theegress LSR (R4)doesnot require an incoming labelfor 4.4.4.0/24.

Instead,R3 (Penultimate LSR) removes the labelbefore forwarding the packet to R4.

R3 forwards the packet as an IP packet, not an MPLS packet, toavoid an unnecessary label lookup at R4.

InMPLS LDP, the label "0" is used to indicate an implicit NULL label (PHP operation).

Why the Answer is "0" (Implicit NULL Label)?

✅Since R4 is the egress LSR, it does not need a label for 4.4.4.0/24.

✅R3 assigns the outgoing label as "0" (Implicit NULL Label)to indicate that the label should be removed before sending to R4.

✅R4 receives the packet as a pure IP packet (no MPLS label).

Why Other Answers Are Incorrect?

❌Any value other than "0"

If R3 assigns a label (e.g., 100), R4 would need to perform anunnecessary MPLS lookup, which is inefficient.

Using "0" ensures PHP occurs, optimizing the forwarding process.

Final Answer: 0

????Reference:Huawei HCIE Datacom – MPLS LDP and Penultimate Hop Popping (PHP)